no word on whether the obamas will attend other events honoring the life and legacy of nelson mandela. >>> now, the story of a new york city homeless man who brings about the old don't judge a book by its cover. >> this is patrick. the kind of driven computer whiz who starts companies in college. he came to new york hoping to meet someone in tech to buy his ideas. he just didn't know it would be the homeless guy on the way to work. >> just has something about, the first time i remember thinking in my head, huh, who is this guy? >> this is leo. as a kid, he was obsessed with science, astronomy, chemistry, physics, but became a father too soon. lost his job, then his home. >> at first, what did you think he wanted? >> i didn't think, you got the wrong guy. he said, hey, this may sound strange, i'm going to approach you with an offer. i'll give you $100 and you spend it however you want to or i'll present you with this new laptop and teach you how to code. instantly, i said in my mind, door number two. >> he would write code for hours, for days. on the banks of the hudson or in a corner